The present invention relates to the field of electronic devices, and more particularly, to assemblies and methods for reducing vibration thereof.
Computers have become commonplace in a great number of applications. Depending upon the data storage and retrieval requirements of a particular application, a computer will typically be configured with a certain combination of memory devices. This is because each particular memory device has particular advantages and disadvantages in terms of cost, speed, and storage capacity.
For example, memory such as cache memory has very fast read and write times, but it is typically one of the most costly types of memories and is often impractical to use on a large scale. On the other hand, writeable disk drives, such as magnetic hard disk drives or optical drives, are much less costly and provide a very large storage capacity, but generally have slower data transfer rates. Additionally, hard disk drives can store data indefinitely even after power is no longer supplied. In between cache memory and disk drives is solid state memory, which is not as fast as cache memory but is less expensive. Further, solid state memory is faster than hard disk drives but still significantly more expensive. Thus, solid state memory is simply not yet practical for very large storage requirements where several Gigabytes or even Terabytes of memory are needed.
Yet, to read or write data to a hard disk drive or optical drive, for example, a read/write head has to be aligned with the disk while it is moving to correctly transfer data to and from the disk. As a result, disk drives typically are susceptible to read and write errors caused by movement or vibration. That is, the read/write head may be jarred out of alignment with the spinning disk causing data transfer errors to occur. Even worse, such vibrations may cause damage to the moving components of the disk drive. This is because disk drives are typically quite sensitive to rotational motion and high G forces at high frequencies. While semiconductor memories such as solid state memories generally are not prone to such vibration damage, as noted above, because of cost it may not be economically feasible to use such memories in high stress environments where movement or vibration is likely if large data storage capacities are required.
As a result, attempts have been made to reduce the effects of shock and vibration on disk drives so that they will be less prone to errors or damage from movement or vibrations. One prior art example is disclosed in U.S. Pat. No. 6,097,608 to Berberich et al. entitled xe2x80x9cDisk Drive Vibration Isolation Using Diaphragm Isolators.xe2x80x9d The patent discloses a diaphragm isolator frame for supporting a disk drive in a rack or other enclosure while providing isolation from undesirable vibrations from other disk drives, components mounted in the enclosure, or from the environment. The diaphragm isolator frame includes a pair of side rails having diaphragm isolators formed of thinned portions of the side rails. Each diaphragm has a centrally located press-pin for supporting the disk drive. Further, the thickness and diameter of the diaphragms may be chosen to provide vibration isolation at a desired frequency.
While such prior art devices may provide some vibration isolation, they still may not be suitable for high stress environments where large amounts of movement or vibration are commonplace, such as in certain mobile applications. For example, computers aboard planes, ground vehicles, etc. may be subject to rather violent shaking that may cause a disk drive mounted according to the prior art to fail or be damaged during writing and/or reading operations. Nonetheless, with the ever increasing advancements in technology, computers with ever higher memory storage capacities are needed that can accommodate such data intensive technologies as well as the rigors of high stress environments.
In view of the foregoing background, it is therefore an object of the present invention to provide a vibration tolerant electronic assembly and related methods.
This and other objects, features, and advantages in accordance with the present invention are provided by a vibration tolerant electronic assembly including a base and a first isolation stage including a first frame, at least one first linear bearing coupling the first frame to the base to constrain movement of the first frame along a first coordinate axis, and at least one first damper for damping movement of the first frame along the first coordinate axis. Additionally, the vibration tolerant electronic assembly may include a second isolation stage including a second frame, at least one second linear bearing coupling the second frame to the first frame to constrain movement of the second frame along a second coordinate axis, and at least one second damper for damping movement of the second frame along the second coordinate axis. Furthermore, a third isolation stage may include a third frame, at least one third linear bearing coupling the third frame to the second frame to constrain movement of the third frame along a third coordinate axis, and at least one third damper for damping movement of the third frame along the third coordinate axis. The vibration tolerant electronic assembly may also include an electronic device coupled to the third frame.
More particularly, the at least one first damper, the at least one second damper, and the at least one third damper may each include at least one spring and/or at least one friction surface. The vibration tolerant electronic assembly may further include at least one first elastomeric coupler coupling the first and second frames together, and at least one second elastomeric coupler coupling the second and third frames together. At least one elastomeric coupler may also be included for coupling the electronic device to the third frame. The at least one first linear bearing, the at least one second linear bearing, and the at least one third linear bearing may each include a pair of parallel spaced apart linear bearings, for example.
Further, the electronic device may be a magnetic disk data storage drive, for example. Additionally, the vibration tolerant electronic assembly may further include a holder carried by the third frame upon which the electronic device is mounted, and a cover coupled to the holder for hermetically sealing the electronic device. The first frame, the second frame, and the third frame each may include metal, for example, and the first isolation stage, the second isolation stage, and the third isolation stage may have different resonant frequencies.
Another aspect of the invention relates to a vibration reduction system for an electronic device which may include a base and a first isolation stage including a first frame, at least one first linear bearing coupling the first frame to the base to constrain movement of the first frame along a first coordinate axis, and at least one first damper for damping movement of the first frame along the first coordinate axis. The vibration reduction system may also include a second isolation stage including a second frame, at least one second linear bearing coupling the second frame to the first frame to constrain movement of the second frame along a second coordinate axis, and at least one second damper for damping movement of the second frame along the second coordinate axis. Further, a third isolation stage may be included to be coupled to the electronic device. The third isolation stage may include a third frame, at least one third linear bearing coupling the third frame to the second frame to constrain movement of the third frame along a third coordinate axis, and at least one third damper for damping movement of the third frame along the third coordinate axis.
Considered in other terms, the vibration reduction system may include a plurality of isolation stages coupled to one another, where at least one isolation stage includes a frame and at least one linear bearing coupling the at least one isolation stage to an adjacent isolation stage to constrain movement of the frame along a coordinate axis. The at least one isolation stage may further include at least one damper for damping movement of the frame along the coordinate axis.
A method aspect of the invention is for reducing vibration of an electronic device and may include coupling a first frame to a base with at least one first linear bearing to constrain movement of the first frame along a first coordinate axis and damping movement of the first frame along the first coordinate axis with at least one first damper. The method may further include coupling a second frame to the first frame with at least one second linear bearing to constrain movement of the second frame along a second coordinate axis and damping movement of the second frame along the second coordinate axis with at least one second damper. Furthermore, a third frame may be coupled to the second frame with at least one third linear bearing to constrain movement of the third frame along a third coordinate axis, and movement of the third frame may be dampened along the third coordinate axis with at least one third damper. Additionally, the electronic device may be coupled to the third frame.
Considered in other terms, the method aspect may include coupling a plurality of isolation stages to one another, where at least one isolation stage includes a frame and at least one linear bearing for coupling the at least one isolation stage to an adjacent isolation stage and constraining movement of the frame along a coordinate axis. The method may also include damping movement of the frame along the coordinate axis using at least one damper.